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Finding the Fourth Proportional to 129.21, 193.81 and 52.15

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Solution

The fourth proportional to 129.21, 193.81 and 52.15 is: 78.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.21 : 193.81 = 52.15 : x
  2. Step 2: Convert to fraction form
    129.21/193.81 = 52.15/x
  3. Step 3: Cross multiply
    129.21x = 193.81 × 52.15
  4. Step 4: Simplify right side
    129.21x = 10,107.19
  5. Step 5: Solve for x
    x = 10,107.19/129.21
  6. Step 6: Final answer
    x = 78.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.